Skarsvåg S
Department of Immunology and Bloodbank, Faculty of Medicine, University of Trondheim, Norway.
Scand J Immunol. 1995 Nov;42(5):572-6. doi: 10.1111/j.1365-3083.1995.tb03698.x.
C4A null genes were determined by RFLP (Taq I) and SSO-probing on PCR-amplified C4-DNA in 51 Scandinavian patients with systemic lupus erythematosus (SLE) and 124 controls. Associations of the alleles DRB10301, DQA10501, DQB10201 had previously been found in this SLE group, as well as increased frequency of HLA-DRB1 and -DQ homozygosity. The frequency of the allele C4AQ0 was increased among the patients (RR = 2.3, P = 0.0172). The SSO-probing revealed additional cases of C4AQ0 homozygotes among the controls, leading to diverging RR values for C4AQ0 homozygotes depending on the technique used. The RFLP method gave an RR of 9.7 (P = 0.0028), while the SSO-probing resulted in an RR of 4.8 (P = 0.0153), demonstrating that unprecise characterization of C4AQ0 in a relatively small material has great effect on the calculated RR. Multiple 2 x 2 tests were performed in an attempt to detect the strongest association of the alleles DRB10301, DQA10501 and C4AQ0 (in linkage disequilibrium). These comparisons showed a trend towards stronger association for DAQ10501 and DRB10301 than for C4AQ0, and no interaction between the HLA alleles and the allele C4AQ0. This may suggest that HLA class II molecules themselves and/or an unknown susceptibility gene located near the DQA1 and DRB1 loci are involved in the pathogenesis of SLE.
采用限制性片段长度多态性（Taq I）和序列特异性寡核苷酸探针杂交技术，对51例斯堪的纳维亚系统性红斑狼疮（SLE）患者及124例对照者经聚合酶链反应（PCR）扩增的C4 - DNA进行检测，以确定C4A无效基因。此前已在该SLE患者组中发现等位基因DRB10301、DQA10501、DQB10201之间存在关联，同时HLA - DRB1和 - DQ纯合子频率也有所增加。患者中C4AQ0等位基因频率升高（相对危险度RR = 2.3，P = 0.0172）。序列特异性寡核苷酸探针杂交技术在对照者中发现了更多C4AQ0纯合子病例，这导致根据所用技术不同，C4AQ0纯合子的RR值有所差异。限制性片段长度多态性方法得出的RR为9.7（P = 0.0028），而序列特异性寡核苷酸探针杂交技术得出的RR为4.8（P = 0.0153），这表明在相对少量样本中对C4AQ0进行不精确的特征描述会对计算出的RR产生很大影响。进行了多次2×2检验，试图检测等位基因DRB10301、DQA10501和C4AQ0（处于连锁不平衡状态）之间最强的关联。这些比较显示，DQA10501和DRB10301之间的关联趋势比C4AQ0更强，且HLA等位基因与C4AQ0等位基因之间无相互作用。这可能提示HLAⅡ类分子本身和/或位于DQA1和DRB1基因座附近的未知易感基因参与了SLE的发病机制。
